1. Field of the Invention
This invention is a device and system which controls the synchronization and switching in a space diversity telecommunications system, where the same data is transmitted to two remote locations, to compensate for propagation vagaries due to weather, movement of the signal source (which may be a satellite), etc. Such a system has particular applicability at microwave frequencies (greater than 1 GHz).
2. Description of the Prior Art
A prior art search was conducted and disclosed the following U.S. patent references:
U.S. Pat. Nos. 3,829,777; 4,015,205; and 4,052,670 disclose space diversity switching systems. They differ from the present invention in that they all require that some type of frame synchronization be superimposed on the data stream. Thus, they do not provide the continuous bit tracking that the present invention is capable of, and they cannot be used with data, e.g., some categories of secure data, which prohibit frame synchronization. The present invention's continuous bit tracking and capability for use on data streams not having frame synchronization makes it much more suitable for asynchronous satellites and for secure data than these prior art systems.
Secondary references are U.S. Pat. Nos. 3,145,341; 3,555,427; 3,975,687; 4,030,040; 4,097,804; and 4,164,709.